Cost-effectiveness of rifampin for 4 months and isoniazid for 6 months in the treatment of tuberculosis infection.

ABSTRACT

OBJECTIVES: To assess the cost-effectiveness ratio of rifampin for 4 months and isoniazid for 6 months in contacts with latent tuberculosis infection. METHODS: The cost was the sum of the cost of treatment with isoniazid for 6 months or with rifampin for 4 months of all contacts plus the cost of treatment of cases of tuberculosis not avoided. The effectiveness was the number of cases of tuberculosis avoided with isoniazid for 6 months or with rifampin for 4 months. When the cost with one schedule was found to be cheaper than the other and a greater number of tuberculosis cases were avoided, this schedule was considered dominant. The efficacy adopted was 90% for rifampin for 4 months and 69% for isoniazid for 6 months. A sensitivity analysis was made for efficacies of rifampin for 4 months of 80%, 69%, 60% and 50%. RESULTS: Of the 1002 patients studied, 863 were treated with isoniazid for 6 months and 139 with rifampin for 4 months The cost-effectiveness ratio with isoniazid for 6 month was € 19759.48/avoided case of tuberculosis and € 8736.86/avoided case of tuberculosis with rifampin for 4 months. Rifampin for 4 months was dominant. In the sensitivity analysis, rifampin for 4 months was dominant for efficacies from 60%. CONCLUSIONS: Rifampin for 4 months was more cost-effective than isoniazid for 6 months.